JPS63134252A - Ink jet printer - Google Patents

Abstract

PURPOSE:To shorten the period of time necessary for a recording operation to become possible, by providing a head unit comprising head elements, a shift register, an ejection energy generating means and a temperature-detecting mechanism on the same block or in a body, and a head unit heating means. CONSTITUTION:When the temperature of a recording head unit 1 is low, a driving voltage for bubble jet elements 2 is cut off, and only a data signal and a transfer clock signal are repeatedly transmitted to a shift register 3A provided in proximity to the elements 2. By this system, it is possible to cause the shift register 3A to generate heat, thereby heating the elements 2 in proximity to the shift register 3A, and it is possible to shorten the period of time necessary for the printer to reach a temperature at which it can operate, as compared to that in a conventional system. Further, it is possible to obtain a uniform temperature distribution over a substantially entire region of a head part constituted of the elements 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an inkjet printer.

[Prior Art] Conventionally, when operating this type of device at low temperatures, the recording quality deteriorates due to the reduction in dot diameter and misalignment of the ejection direction due to factors such as the viscosity of the ink, compared to when the head is operated at room temperature. The recording operation is prohibited until the ambient temperature is detected and stable ink ejection is possible. During the prohibited period, the temperature around the head is raised using a heat generating means such as a resistor or a transistor provided in the head unit having the recording head.

[Problem to be Solved by the Invention 1] However, since many of these types of devices that require high speed have integrated heads, heat generating means are disposed near the ink ejection ports. Therefore, it takes a long time for the temperature of the ink near the ejection opening, that is, the ink involved in recording, to reach the appropriate temperature. That is, in the conventional apparatus of this type, there has been a problem that it takes a long time V until the recording operation becomes possible.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a head element having a plurality of ink ejection ports, a shift register for specifying the ejection ports to be operated in the head element, A head unit includes an ejection energy generating means for ejecting ink from an ejection port designated by a shift register, a temperature detection mechanism, etc., formed on the same block or integrally, and a head unit configured to detect a temperature detected by the temperature detection mechanism below a predetermined temperature. When the energy is low, the ejection energy generating means is controlled to prohibit ink ejection,
The head unit is heated by generating heat from operating the shift register.

[Function] According to the present invention, it becomes possible to directly heat the vicinity of the recording head, and the time required for a recording operation to become possible can be shortened compared to the conventional example.

[Example〕 Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing the configuration of an embodiment of the present invention, and the recording head unit 1 has 128 ink ejection nozzles.
Bubble Jet Niremen] (hereinafter referred to as LIE) 2 is arranged in a pot, making it possible to form one line of dots. A head drive unit made by CO5 which integrally forms a shift register for parallel conversion and a driver for driving BJE 2 according to the output of the shift register, 4 is a heater for warming the recording head unit 1, and 5 is a recording head unit. 1 temperature detection sensor, 6
7 is an ink injection valve, and 7 is an ink discharge valve. The printer controller 8 is composed of, for example, a microprocessor, and exchanges various signals such as recording data, control data, and the output of the sensor 5 with the recording head unit 1 via a connector 9. Further, this printer controller 8 controls each part of the recording head unit 1 according to the recording processing procedure shown in FIG.

FIG. 2 is a block diagram showing the configuration of the head drive unit 3, and the signals in the diagram indicate signals sent from the printer controller 8. As shown in FIG. The shift register 3A is a serial DAT sent from the printer controller 8.
A is taken in in synchronization with the CLOCK signal, and converted into separate DATA so as to correspond to each of the ink ejection nozzles of BJE 2.

The driver 3B is enabled by the input of the HEATI signal, and BJE is activated according to the output signal of the shift register 3A.
A drive signal is sent to the electro-thermal conversion element provided in the second ink discharge nozzle.

The head drive power supply that supplies electrical energy to the electro-thermal conversion element in BJE 2 and the connection between BJE 2 and BJE 2 are connected to the voltage (: T
I.

Controlled by a signal.

FIG. 3 is a flowchart showing an example of the recording processing procedure according to this embodiment.

First, when the power is turned on, the temperature of the recording RAD unit 1 is detected by the sensor 4 in step Sl.

In step S2, the temperature detected in step S1 is
It is determined whether the temperature meets a predetermined record9
In step S1), if the temperature of the recording head unit 1 is low, the process advances to step S3.

In step S3, the voltage CTL signal is turned "off" to stop supplying power to the electro-thermal conversion element in the BJE 2.

In such a state, even if HEA 3 enters the driver 3B and a drive signal is output from the driver 3B to the electro-thermal conversion element, the ink in the BJE 2 will not be ejected. 4 is turned on to heat the RAD unit 1 for recording.

In step S5, "on" and "off" signals are alternately supplied to the shift register 3A in synchronization with the (:LOC) signal. When the shift 1 register 3A receives such a signal, the shift register 3A Generates heat and heats the vicinity of BJE 2.

Here, CuO2 constituting the shift register 3A generally generates only a small amount of heat when there is no CLOCK signal, but generates considerable heat near the limit of the operable frequency. In particular, in the shift register 3A having a large number of bits as in this embodiment, the amount of heat generated is particularly large.

Further, as shown in FIG. 1, since the head drive unit 3 including the shift register 3A is provided near the BJE 2, it is possible to easily and uniformly heat the ink related to recording in the BJE 2 and its vicinity. be able to.

When the heating operation as described above continues and the recording head unit 1 reaches a temperature suitable for recording, an affirmative determination is made in step S2, and the process proceeds to step S6.

In step S6, the voltage CTL signal is set to 0" to put the BJE 2 in a recording standby state.

In step S7, one line of recording data (DATA) is transferred to the shift register 3A through the serial data line.
Set to .

In step S8, the HEAT signal is turned on, and the driver 3B is turned on in accordance with the output of the shift register 3A.
Recording for one line is performed by driving the electro-thermal conversion element in the JEZ.

Thereafter, the process advances to step S9 and normal recording processing is performed.

Then, the process returns to step S1 as appropriate according to predetermined conditions, and the process is performed in accordance with the procedure described above.

As explained above, according to this embodiment, when the temperature of the recording head unit 1 is low, the drive voltage of the BJE 2 is cut off, and only the data signal and transfer lock are transferred to the BJE.
By causing the shift register 3A to generate heat simply by repeatedly transmitting data to the shift register 3A located close to the shift register 3A, it becomes possible to heat the BJE 2 located close to the shift register 3A, thereby improving printer operation. This makes it possible to shorten the time it takes to reach a possible temperature compared to the conventional example.

Furthermore, in this embodiment, it is also possible to obtain a uniform temperature distribution over almost the entire area of the head section formed by the plurality of BJEs 2.

In this embodiment, the driving voltage of the BJE 2 is cut off to inhibit the recording operation during heating, but it is also possible to inhibit the recording operation by maintaining the HEAT signal in the "off" state.

Note that in this embodiment, the head element and the shift register are arranged on the same block, but the present invention is not limited to this, and the head element and the shift register may be configured as one unit. .

[Effects of the Invention] As explained above, according to the present invention, it is possible to directly heat the vicinity of the recording head, and the time required for recording to become possible can be shortened compared to the conventional example. is obtained.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the configuration of an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a head drive unit, and FIG. 3 is a flowchart showing an example of the processing procedure of the print controller shown in FIG. be. 1... Recording head unit, 2... Bubble jet element (BJE), 3...
・Head drive unit, 3A...Shift register, 3B...Driver, 4...Heater, 5...Sensor, 6...Ink injection valve, 7...Ink discharge valve, 8. ...Print controller, 9...Connector. Figure 2 Figure 3

Claims (1)

[Scope of Claims] A head element having a plurality of ink ejection ports, a shift register that specifies the ejection port to be operated in the head element, and ejection energy generation to eject ink from the ejection port specified by the shift register. and a temperature detection mechanism formed on the same block or integrally; and a head unit that controls the ejection energy generating means to eject ink when the temperature detected by the temperature detection mechanism is lower than a predetermined temperature. An inkjet printer characterized in that the inkjet printer is provided with means for inhibiting the operation of the shift register and heating the head unit by causing the shift register to generate heat.